Papa, you have been given very good advice regarding venting (which is refreshing to see). Even though our batteries and many others (both AGM & flooded) are considered “sealed” batteries, all lead-acid automotive batteries can vent gas in extreme situations. For that reason, we always recommend that any battery installed in an enclosed location be properly-vented to the outside. In addition to the Group 31 battery Michael mentioned, our group 27, 51, 34C, and 78 batteries all have ports for connecting a vent hose, although you'll probably want to stick with either a Group 27 or Group 31 battery for your application. Although people do it anyway, we would never recommend installing an unvented battery in any enclosed space, because there's a legitimate, albeit unlikely, safety risk involved.
For example, IF there is a voltage regulator failure, and IF the battery is severely overcharged, and IF this goes unnoticed, and IF the battery vents because the internal pressure exceeds the release pressure of the vents, the gasses are both flammable and toxic. This may sound like a lot of “ifs,” but attorneys and engineers get paid to plan for every worst-case scenario. If anyone has any questions about our batteries, I'll do my best to answer them.
Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
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